TOXICOLOGY,
PHARMACOKINETICS
Questions And
Answers
, PHARMACOLOGY, TOXICOLOGY, PHARMACOKINETICS
1. Two dose-response curve response plotted on the same graph showed sigmoid
curves having the same slope and height. T curve is located to the right of the A
curve. Which of the following statements is/are correct regarding curves A an:
I. A is more effective than B
II. A is more potent than B
III. A and B have the same ceiling dose
IV. B is the graph produced when A is given with its competitive antagonist
V. B is the graph produced when A is given with its non-competitive
antagonist
a. Only I and III are correct
b. Only II, III and IV are correct
c. Only II and IV are correct
d. Only III and V are correct
e. Only V is correct
2. Two dose-response curve plotted on the same graph showed sigmoid curves A and B,
where A is at the left of the graph with the height greater than B. Which of the
following statements is/are correct regarding curves A and B?
I. A and B has equal efficacy
II. A and B have equal potency
III. B is a partial agonist of A
IV. B is the graph produced when A is given with its competitive antagonist
V. B is the graph produced when A is given with its non-competitive
antagonist
, a. Only I and III are correct
b. Only II, III and IV are correct
c. Only II and IV are correct
d. Only III and V are correct
e. Only V is correct
3. The cumulative number of subjects who display a certain rersponse or effect to a
drug is plotted on a graph as shown below. The graph on the left represents
beneficial effect while the graph on the right represents toxic effect, what is the
therapeutic index of the drug?
a.0.5 b. 1.5 c. 2.5 d.4.0
e. 5.0
4. An administration of one drug leads to a shift in the log dose-response curve of
another drug to the left a range in the maximal efficacy, this is called
a. Agonism
b. Partial agonism
c. Non-competitive antagonism
d. Competitive antagonism
e. Potentiation
5. The action of this drug is dependent on a colligative property
a. Mannitol
b. Cocaine
c. Reserpine
d. Furosemide
e. Losartan
6. Whiich of the following drug groups have mechanisms of aaction that involve
binding to enzymes as target protiens
a. Benzodiazepines
b. Barbiturates
c. Calcium channel blockers
d. Non-steroidal anti-inflammatory agents
e. Phenothiazine antipsychotics
7. Voltage-gated ion channels serve as site of actions for drugs such as
I. Diltiazem and Nifedipine
II. Lidocaine and Procaine
III. Captopril and Losartan
a. I only
b. I and II
, c. III only
d. I and III
e. I, II, and III
8. Drugs with mechanism of action that involves Tubulin-binding leading to loss of
function of the structural protien include
a. Cyclosporine
b. Neostigmine
c. Colchicine
d. Glibenclamide
e. Metformin
9. What type of protien is primarily targeted by Digitalis glycosides when they exert
their effect on the heart?
a. Receptors
b. Ion channels
c. Enzymes
d. Transporters
e. Structural protiens
10. Which of the following features cahracterize nicotinic, GABA-A, and Glutamate
receptors?
a. Thay control the movements of ions and out of the cell
b. Their action is mediated bysecondary messengers
c. They all have excitatory effect on the cell membrane
d. They are located on the cytoplasm
11. Which of the following drugs bind to receptors located at the cell membrane?
a. Thyroid hormone
b. Prednisone
c. Estrogen
d. Insulin
e. Vitamin D
12. Cyclic Adenosine Monophophate (cAMP) is generated as a secondary messenger by
the action of the enzyme Adenylyl Cyclase. The substrate for the synthesis of cAMP
is
a. AMD
b. ADP
c. ATP
d. GTP
e. Adenosine
13. Stimulation of Beta-adrenoceptor, a G-protien-linked receptor involves a
generation of a secondary messenger known as
a. IP3
b. cGTP
c. DAG
d. cAMP
e. Calcium ions
14. What is the mechanism of action of Sildenafil, a drug popularly known as viagra?
a. Inhibits phosphodiesterase (PDE) leading to increase cAMP
b. Inhibits PDE leading to increase cGMP
c. Stimulates adenylyl cyclase leading to increase cAMP
d. Stimulates guanylyl cyclase leading to increase cGMP
e. Inhibits phosphodiesterase leading to increase cGMP